1. Field of the Invention
The present invention relates to mounting of semiconductor package components to carry out surface mounting of the semiconductor package components on a substrate, and relates to a mounting structure with good durability and a manufacturing method therefor.
2. Related Art of the Invention
Conventionally, for a semiconductor package component like a BGA (Ball Grid Array) such that ball electrodes are formed on the undersurface, a durably reliable mounting structure has been realized through reinforcement of the semiconductor package component, for example, (i) by allowing a reinforcement resin such as an under-fill resin or the like to flow into the gap between the semiconductor package component and the substrate so that the resin will be hardened, or (ii) by applying a corner bond adhesive on the edge part of the semiconductor package component so that the adhesive will be hardened.
Each of these methods adopts a step of carrying out reinforcement utilizing an adhesive after solder bonding of a semiconductor package component to a substrate.
On the other hand a mounting method is also known that performs, by applying an adhesive in a step before the reflow step, hardening of the adhesive and solder bonding simultaneously.
FIGS. 10A-10D show an example of such a mounting step, in which the applying step of an adhesive is performed between the mount step of a semiconductor package component and the reflow step (see, for example, Japanese Patent Laid-Open No. 2010-258173).
In FIGS. 10A and 10B, a semiconductor package component 3 is mounted on cream solder 5 applied on electrodes 2 of a substrate 1 so that ball electrodes 4 of the semiconductor package component 3 abut thereon.
In FIG. 10C, a heat-hardening resin 9 is applied so as to join the substrate 1 to the semiconductor package component 3.
Moreover, in FIG. 10D, the substrate 1 with the semiconductor package component 3 mounted, on which the heat-hardening resin 9 has been applied, goes through reflow treatment. When the reflow treatment is performed, the metal of the ball electrodes 4 and the cream solder 5 are melted and mixed to become a bonding metal 7. At this point, since the heat-hardening resin 9, which is a heat-hardening resin, is in an unhardened state, the semiconductor package component 3 moves to an appropriate position owing to a self-alignment effect of solder of the melted bonding metal 7 being sandwiched between the electrodes 2 of the substrate 1 and the electrodes on the side of the semiconductor package component 3.
After the heat-hardening resin 9 is further heated to be hardened, the solder of the bonding metal 7 cooled to a temperature below the solder melting point is solidified, and the electric connection of the semiconductor package component 3 to the substrate 1 and the mechanical link between them are completed via one heating step.